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Spatiotemporal modes of global sea surface temperature variability

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Science China Earth Sciences 2017年第3期60卷 508-516页

作者： zhang xiangming CHEN Chen LIAN Tao CHEN DaKe State Key Laboratory of Satellite Ocean Environment Dynamics Second Institute of OceanographyHangzhou 310012China Lamont-Doherty Earth Observatory of Columbia University New York 10027USA

This study identifies the salient global modes of sea surface temperature variability based on 145 years of HadlSST *** the traditional mode identification by EOF analysis,a combination of wavelet and EOF analysis is used to extract the leading modes at distinct time *** spatial patterns of some well-known regional modes are recovered,with the global connection and frequency content of these modes being *** analysis indicates that,in terms of global influence,the Pacific Ocean is the major player,and the tropical Pacific is the center of action on various time *** Atlantic Ocean has its own outstanding modes,but their global impacts are not as strong as those from the *** Indian Ocean generally shows a passive response to the Pacific,with a basin-wide pattern in the *** some preliminary theoretical attempts,how to elucidate the dynamics underlying the global modes of sea surface temperature variability is still an open question.

关键词： Global mode Wavelet EOF

Assessment of intraseasonal variabilities in China Ocean Reanalysis(CORA)

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Acta Oceanologica Sinica 2016年第3期35卷 90-101页

作者： zhang Min ZHOU Lei FU Hongli JIANG Lianghong zhang xiangming Key Laboratory of Coastal Disaster and Defence of Ministry of Education Hohai University State Key Laboratory of Satellite Ocean Environment Dynamics Second Institute of OceanographyState Oceanic Administration Key Laboratory of Marine Environment Information Technology National Marine Data and Information ServiceState Oceanic Administration

A regional reanalysis product-China Ocean Reanalysis（CORA）-has been developed for the China＇s seas and the adjacent areas. In this study, the intraseasonal variabilities（ISVs） in CORA are assessed by comparing with observations and two other reanalysis products（ECCO2 and SODA）. CORA shows a better performance in capturing the intraseasonal sea surface temperatures（SSTs） and the intraseasonal sea surface heights（SSHs） than ECCO2 and SODA do, probably due to its high resolution, stronger response to the intraseasonal forcing in the atmosphere（especially the Madden-Julian Oscillation）, and more available regional data for assimilation. But at the subsurface, the ISVs in CORA are likely to be weaker than reality, which is probably attributed to rare observational data for assimilation and weak diapycnal eddy diffusivity in the CORA model. According to the comparison results, CORA is a good choice for the study related to variabilities at the surface, but cares have to be taken for the study focusing on the subsurface processes.

关键词： China Ocean Reanalysis(CORA) intraseasonal variability Madden-Julian Oscillation ocean reanalysis product

In vivo mechanical study of helical cardiac pacing electrode interacting with canine myocardium

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Acta Mechanica Sinica 2007年第3期23卷 275-280页

作者： xiangming zhang Nianke Ma Hualin Fan Guodong Niu Wei Yang Department of Engineering Mechanics Tsinghua University Beijing 100084 China Fuwai Angiocardiopathy Hospital Beijing 100037 China Zhejiang University Hangzhou 310027 China

Cardiac pacing is a medical device to help human to overcome arrhythmia and to recover the regular beats of heart. A helical configuration of electrode tip is a new type of cardiac pacing lead distal tip. The helical electrode attaches itself to the desired site of heart by screwing its helical tip into the myocardium. In vivo experiments on anesthetized dogs were carried out to measure the acute interactions between helical electrode and myocardium during screw-in and pull-out processes. These data would be helpful for electrode tip design and electrode/myocardium adherence safety evaluation. They also provide reliability data for clinical site choice of human heart to implant and to fix the pacing lead. A special design of the helical tip using strain gauges is instrumented for the measurement of the screw-in and pull-out forces. We obtained the data of screw-in torques and pull-out forces for five different types of helical electrodes at nine designed sites on ten canine hearts. The results indicate that the screw-in torques increased steplike while the torque-time curves presente saw-tooth fashion. The maximum torque has a range of 0.3-1.9 Nmm. Obvious differences are observed for different types of helical tips and for different test sites. Large pull-out forces are frequently obtained at epicardium of left ventricle and right ventricle lateral wall, and the forces obtained at right ventricle apex and outflow tract of right ventricle are normally small. The differences in pull-out forces are dictated by the geometrical configuration of helix and regional structures of heart muscle.

关键词： Cardiac pacing Helical electrode Acute Interactions Myocardium

Variability of sea surface height in the South China Sea and its relationship to Pacific oscillations

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Acta Oceanologica Sinica 2015年第12期34卷 80-92页

作者： PEI Yuhua zhang Rong-Hua zhang xiangming JIANG Lianghong WEI Yanzhou College of Oceanic and Atmospheric Sciences Ocean University of China State Key Laboratory of Satellite Ocean Environment Dynamics Second Institute of Oceanography State Oceanic Administration Key Laboratory of Ocean Circulation and Waves Institute of Oceanology Chinese Academy of Sciences

The spatio-temporal variability modes of the sea surface height in the South China Sea（SCS-SSH） are obtained using the Cyclostationary Empirical Orthogonal Function（CSEOF） method, and their relationships to the Pacific basin scale oscillations are examined. The first CSEOF mode of the SCS-SSH is a strongly phase-locked annual cycle that is modulated by a slowly varying principal component（PC）; the strength of this annual cycle becomes reduced during El Ni？o events（at largest by 30% off in 1997/98） and enhanced during La Ni？a events. The second mode is a low frequency oscillation nearly on decadal time scale, with its spatial structure exhibiting an obscure month-dependence; the corresponding PC is highly correlated with the Pacific Decadal Oscillation（PDO） *** independent oscillations in the Pacific are isolated by using the independent component（IC） analysis（ICA）method, and their effects on the SCS-SSH are examined. It is revealed that the pure ENSO mode（which resembles the east Pacific ENSO） has little effect on the low frequency variability of the SCS-SSH while the ENSO reddening mode（which resembles the central Pacific ENSO） has clear effect. As the ENSO reddening mode is an important constituent of the PDO, this explains why the PDO is more important than ENSO in modulating the low frequency variability of SCS-SSH. Meridional saddle like oscillation mode, the Kuroshio extension warming mode, and the equatorial cooling mode are also successfully detected by the ICA, but they have little effect on the low frequency variability of the SCS-SSH. Further analyses suggest the Pacific oscillations are probably influencing the variability of the SCS-SSH in ways that are different from that of the sea surface temperature（SST） in the SCS.

关键词： South China Sea sea surface height ENSO PDO

Kinematics and Dynamics Analysis of Drive Mechanism of Parallel Four-Bar Energy-Saving Pumping Unit

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Wuhan University Journal of Natural Sciences 2012年第1期17卷 73-78页

作者： zhang xiangming YANG Xia GUO Zhao School of Optoelectronics Huazhong University of Scienceand Technology Wuhan 430074 Hubei China School of Mechanical and Electrical Engineering WuhanInstitute of Technology Wuhan 430073 Hubei China

The conventional beam pumping unh consumes a large amount of energy due to its unsmooth movement. In this work, we design a new energy-saving parallel four-bar pumping unit and derive the kinematic and dynamic law of the drive mechanism systematically by theoretical method. For the given target technical parameter, the theoretical results are verified by computer simulation, which shows that the simulation dynamic curves agree well with the theoretical ones and the calculated power consumption is low. Theoretical analysis shows that the newly designed pumping unit reduces average power by 28.8% compared with its conventional counterpart. The much lower theoretical energy consumption and the better dynamic performance indicate that the new energy-saving pumping unit is well designed and will have a significant application prospect.

关键词： parallel four-bar pumping unit drive mechanism kinematics dynamics energy consumption

IN VIVO CHARACTERIZATION OF ATTACHMENT SAFETY BETWEEN CARDIAC PACING LEAD AND CANINE HEART MUSCLE

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Acta Mechanica Solida Sinica 2007年第3期20卷 189-197页

作者： zhang xiangming Niu Guodong Ma Nianke Fan Hualin Zhao Yong Yang Wei Department of Engineering Mechanics Tsinghua University Beijing 100084 China Fuwai Angiocardiopathy Hospital Beijing 100037 China Medtronic Cardiac Rhythm Management Minneapolis 55432-3576 USA

In vivo experiments of screwing the electrode of canine hearts and assigning external excitation on the lead-myocardium interface was carried out to evaluate the lead/myocardium adherence safety. The electrode is specially designed to host a measurement unit of strain gauges. We obtained the lead/heart interactions data from 12 dogs under natural heart beating and beating with external excitations. The data recorded from the acute phase and the chronic phase of pulling out pacing leads were compared with each other. The electrode/heart interaction is caused by the heart beat and influenced by the lung breath. This process induced tolerable damage to the lead or myocardium. The interaction decreases as the frequency of external excitations increases. The lead is more likely to be detached from myocardium under higher excitation frequency. At the same implanting sites, safer pacing lead/myocardium attachment can be realized in the chronic tests than in the acute tests.

关键词： biomechanics pacing in vivo myocardium attachment safety

Optimal Design of a High-power Friction Brake Based on Improved Genetic Algorithm 36

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Optimal Design of a High-power Friction Brake Based on Impro...

LATERAL PHOTOEFFECT OF ULTRATHIN METAL FILMS AND INDIUM TIN OXIDE FILMS DEPOSITED ON n-Si SUBSTRATE

第36届中国控制会议

作者： LI Pengfei WANG Guangsen zhang xiangming MA Mingzhong National Key Laboratory of Science and Technology on Vessel Integrated Power System Naval Univ. of Engineering

ISBN: (纸本)9781538629185

For the emergency braking of a large-capacity inertia flywheel energy storage system, this paper refers to a rapid braking scheme based on the friction brake. However, its difficulty lies in the design of a high power brake, which includes temperature, volume, power and so on. The present multi-objective optimization algorithm is not available for engineers due to its complicated design, much difficulty in implementation, and time-consuming calculation. Therefore, this paper has proposed an improved genetic algorithm to solve multiple constraints, which can be changed into a problem of common constraint. Moreover the algorithm is convenient for designers because of its ideal convergence, universality and flexibility. The prototype testing proves the braking scheme of the large-capacity flywheel energy storage system to be feasible and the optimized algorithm for the friction brake to be effective, which can play a certain guiding role in engineering practice.

关键词： friction brake genetic algorithm multi-objective optimization penalty function

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Chinese Physics Letters 1989年第7期6卷 313-316页

作者： CHEN Tupei HUANG Bingzhong ZHUO Jian LI Weidong zhang xiangming Department of Physics Zhongshan UniversityGuangzhou

Uliraihin metal films and indium tin oxide(ITO)films were prepared by vacuum evaporation on n-iype Si *** structures exhibit interesting phoioelecironic properties,and lateral photovoltage was *** photovoltaic output can be a linear function of the position of light spot(localized illumination)with zero output for the light spot in the center;it reverses sign when the light spot scans from one side to the other side of the center *** mechanism for this photovoltaic behavior is discussed.

关键词： illumination RATE vacuum

农业区域规划背景下的农村成人教育发展对策——以福建省为例

维普期刊数据库评论

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教育发展研究 2006年第24期26卷 63-66页

作者：张祥明福建教育学院教育系福州350025

农村成人教育的发展要基于省情,依据农业发展区域布局进行规划,实施区域农村成人教育。发展应该从强化政府和教育主管部门的责任义务,针对农村成人教育实际的课程设置、教材编写,对分管农村成人教育的领导和教师进行培训,组建区域农村... 详细信息

农村成人教育的发展要基于省情,依据农业发展区域布局进行规划,实施区域农村成人教育。发展应该从强化政府和教育主管部门的责任义务,针对农村成人教育实际的课程设置、教材编写,对分管农村成人教育的领导和教师进行培训,组建区域农村成人教育集团,实现教育资源共享,探索农村成人教育的市场化运作,加快农村成人教育信息化网络化建设步伐等几个方面来进行。

关键词：农村成教现状农业发展区域布局区域农村成人教育发展对策